[DOCS] Errors in documentation - Mailing list pgsql-docs

Hello,

Please consider committing attached patches to the documentation.
A pair of the patches I sent before (see
https://www.postgresql.org/message-id/374e84e6-f89b-4d0a-652c-cb2449f0bfc4%40gmail.com),
but they weren't committed.
If some of these patches are not valid or raise any questions, please
let me know.

Best

--
Alexander Lakhin
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company